1. Field of the Invention
The present invention relates to a magnetic head slider used for a magnetic disc unit.
In recent years, a strong demand for increasing the density of magnetic recording has arisen. Therefore, the magnetic disc unit has been made compact, its performance has been highly enhanced, and its cost has been reduced. In accordance with the recent tendency, it is desired to develop a thin film magnetic head of high performance and low cost. In order to meet the demand, a horizontal magnetic head, in which a thin film pattern forming surface is arranged in parallel with an air bearing surface, has been proposed. The reason is described as follows. In the case of a horizontal magnetic head, it is easy to form flying rails having specific shapes. Therefore, it is possible to realize a magnetic head capable of flying stably close to the disc surface, and further it is easy to reduce a portion to be machined in the manufacturing process, and furthermore the horizontal magnetic head can be easily handled and the cost can be lowered.
2. Description of the Related Art
For the above reasons, there is proposed a magnetic head slider capable of being manufactured in a manufacturing process in which machining is seldom conducted. This magnetic head slider is disclosed in Japanese Unexamined Patent Publication No. 9-81924, the tile of which is "Thin film magnetic head slider and electrostatic actuator thereof" which discloses a magnetic head slider on which a horizontal head element is mounted. After flying rails and thin film head elements have been formed on a substrate via a sacrificial layer, a conductor to be used as a terminal connecting section is formed by means of plating and, at the same time, a slider body is formed by a conductor.
Another prior art is disclosed in Japanese Unexamined Patent Publication No. 4-265584. According to the above patent publication, in order to accurately control a position of a magnetic head element on a recording track, a plurality of sliding sections surrounding the magnetic head element are fixed to a head support via piezoelectric elements which can be extended and contracted in the vertical direction and used for controlling the posture of the magnetic head and the magnetic head elements are fixed to the head support via a support section.
Japanese Unexamined Patent Publication No. 6-314479 discloses a magnetic head slider, which is composed as follows. An angle formed between a straight line connecting a magnetic or geometrical center of a reading head with that of a writing head and a tangent of a track at the head position is made constant in the entire seek range, so that both a yaw angle of the reading head and that of the writing head are made constant to provide a magnetic disk unit of high reliability. The position of the dual head is detected by a position detecting means. According to a result of the detection, a yaw angle adjusting means is driven, and the angle formed between the straight line connecting the magnetic or geometrical center of the reading head with that of the writing head and the tangent of the track at the head position is made constant. Due to the foregoing, both the yaw angle of the reading head and that of the writing head are made constant in the entire seek range.
According to Japanese Unexamined Patent Publication No. 8-180623, in order to enhance the positioning accuracy of a magnetic head in a magnetic disc unit so as to increase the density of recording, at a forward end portion of a load arm, there are provided a rotary spring for supporting a rotating slider and an inching drive means for moving the slider in the track direction relative to the load arm.
In the magnetic head slider described in the above Japanese Unexamined Patent Publication No. 9-81924, information recorded on a medium is read and written by a head element provided on this slider. In this case, the head element is composed of MR head exclusively used for reading and an inductive head used for writing. These MR head and inductive head are laminated in this order.
When MR head and the inductive head line up in a straight line on the track of the medium in the case of reading and writing, the track density must be a maximum. However, in an actual reading and writing operation, an actuator is rotated round the center of a spindle located outside of the medium from the inside to the outside in the effective range of the disc-shaped medium. Therefore, in the major part of the track, MR head and the inductive head are shifted from a straight line parallel to the track. A value of cos .theta. makes a contribution to the reading and writing of a signal, wherein .theta. is an angle formed between a straight line connecting MR head with the inductive head and a tangent which represents a direction of the track. Therefore, in the case where .theta.=0 is not satisfied, the signal intensity is lowered. For the above reasons, it is impossible to increase the density of the track to the maximum.